Hidden Sectors through the Higgs and kinematic portals

A real singlet scalar DM particle coupled to the SM through the Higgs portal is the most minimal model of a hidden sector. The stability of the DM requires an ad hoc discrete symmetry. The absolute stability of DM might be guaranteed by a gauge symmetry, which can be spontaneously broken by scalars in the HS that mix with the Higgs boson through the Higgs portal. A hidden U(1) gauge field may also couple to the VS through kinetic mixing. The resulting Z’ boson (dark Z) would be partially invisible and may have eluded searches (at the LHC and elsewhere). A light dark Z (dark photon) could also exist, implying a self-interacting DM particle. Another possibility is that gauge fields in the HS may be confined, leading to a way to address the EWSB problem and possibly to peculiar
signatures, such as multi-particle displaced tracks at the LHC.

WP4 aims at exploring new hidden sector scenarios and to look for their experimental signatures at the LHC and with the NA62 experiment.

Team: R. Argurio (ULB), B. Clerbaux (ULB), E. Cortina (UCL), T. Hambye (ULB), S. Lowette (VUB), F. Maltoni (UCL), A. Mariotti (VUB), M. Tytgat (ULB), PhD7, PD1, PD5, PD6, PD10, PD11.